This is because most better educated people are usually smarter, more intelligent, more clever, more well-read, more knowledgeable, more skilful, more experienced, more sophisticated, and have more access to more information than the average uneducated or lowly-educated person.
In general, better educated people are much more demanding and much more discriminatory when it comes to the types of products and services that they want to and are interested in buying and using for themselves.
They expect to buy and use higher quality products and services for themselves, such as designer brands, as a means of publicly displaying and reflecting their higher status in society to other people.
They normally shun away from lower quality products and services, such as generic brands, because they think that and they also feel that low quality products and services are insufficient and inadequate to meet their high expectations and overt personal needs.
Of course, not every single better educated person thinks in such discerning ways, but there are definitely a lot of better educated people around the world, who are much more attracted to and interested in very expensive high quality products and services that are made by the top designer label brands of the most famous designer companies/ businesses in the world.